The present invention generally relates to prosthodontic casts, and more particularly to a two-part dowel pin which permits a simple separation and replacement of a dental model cast or segments thereof on a base cast.
Various dowel pins for permitting the separation and replacement of segments of a dental model cast on a base cast are already known in the prior art. Such dowel pins are shown in the Applicant's own U.S. Pat. Nos. 3,875,665 and 3,932,939, to which reference should be made. However, the dowel pins disclosed in the above mentioned patents, and also in the prior art, have a one piece construction. Accordingly, when removing the dental model segment, the dental model segment must be held firmly and usually wiggled in order to remove the prior art dowel pins from their associated sleeves in the base cast, thereby requiring a force to be placed upon the dental model segment which could cause damage to both the segment being removed and segments adjacent thereto.
Additionally, if the shank of the prior art dowel pin is damaged in some way, there is no convenient way of replacing the dowel pin in the segment without causing damage to the segment because the entire prior art dowel pins are fixedly secured in the segment.
Furthermore, it is difficult to cut the dental model cast into segments when the shanks of the prior art dowel pins are extending outwardly therefrom.